DG Void Killer
DG SRTM Void Killer works by mixing SRTM and SRTM30 data, it detects
a void (lack of elevation data) and then it gets the information of
an user supplied GTOPO30 tile.Terrain formats:SRTM30 and SRTM3.

DG Line of Sight
The Purpose of this enhancement is by using DGTV terrain and gps great
viewing capabilities, make a program to make line of sight analysis
with a simple add-on on the menu bar, that you can see on the picture
on the side:
Terrain formats:GTOPO30, SRTM30, SRTM3, ETOPO5 and DRC.
GPS formats: Ozi Explorer, GPX Exchange, GPS Utility, GTM.